(22 days)
The Roche Diagnostics Magnesium reagent is intended for use for the quantitative determination of magnesium in human serum, plasma, and urine on automated clinical chemistry analyzers.
Magnesium, in the presence of EGTA, is coupled with xylidyl blue in an alkaline solution. Magnesium + xylidyl blue alkaline -> purple complex. EGTA in the reagent complexes with calcium, so that only magnesium reacts with the indicator. The intensity of the color of the purple complex formed is proportional to the magnesium concentration and can be measured photometrically.
The provided text is a 510(k) summary for a medical device, the Roche Diagnostics Magnesium Reagent. It is a premarket submission to the FDA for a Class I in vitro diagnostic device, and as such, the focus is on demonstrating substantial equivalence to a predicate device rather than presenting detailed clinical study results with acceptance criteria in the same way one would for a novel medical imaging AI device.
Therefore, much of the requested information (like effect size of human readers with/without AI, expert ground truth adjudication, sample size for training sets, etc.) is not applicable to this type of submission for this specific device.
However, I can extract and interpret the information that is present in the context of device performance and substantial equivalence:
Device: Roche Diagnostics Magnesium Reagent
1. Table of Acceptance Criteria and Reported Device Performance
For an in vitro diagnostic reagent like this, "acceptance criteria" are typically defined by demonstrating that the new device performs comparably to a legally marketed predicate device, especially in terms of accuracy, precision, linearity, and interference. The document primarily focuses on similarities and asserting substantial equivalence based on these.
| Characteristic | Acceptance Criteria (Implied by Predicate Comparison) | Reported Device Performance (Roche Diagnostics Magnesium Reagent) |
|---|---|---|
| Intended Use | Measurement of magnesium in human serum, plasma, and urine | Measurement of magnesium in human serum, plasma, and urine (identical) |
| Sample Type | Serum, plasma, CSF; Urine, acidified to pH 1 | Serum, plasma, CSF; Urine, diluted with 0.9% saline or water (difference noted, but implied to be equivalent for clinical utility) |
| Use on Automated Chemistry Analyzers? | Yes | Yes (identical) |
| Test Principle | Magnesium reacted with calmagite (predicate) | Magnesium reacted with xylidyl blue (difference noted, but implied to produce equivalent results) |
| Calibration | Two points, blank (saline) and ~1.4 mmol/L magnesium | Two points, blank (saline) and ~1.4 mmol/L magnesium (identical) |
| Calibration Stability | Perform new calibration every 24 hours, and with bottle/reagent lot change | Perform new calibration with bottle or reagent lot change (improved stability: less frequent calibration required) |
| Kit Configuration, Reagent Preparation | R1, R2 liquid, ready-to-use | R1, R2 liquid, ready-to-use (identical) |
| Reagent On-board Stability | 1 week | 3 weeks (improved stability) |
| Overall Performance | Substantially equivalent to predicate | Substantially equivalent to predicate as demonstrated by specific data in Section V (not provided in this excerpt but referenced). |
Note: The document explicitly states: "Specific data on the performance of the system have been incorporated into the draft labeling in Section V of this submission." This section itself is not provided, but it would contain the detailed studies (e.g., accuracy against a reference method, precision, linearity, interference studies) that formally define performance parameters and criteria comparisons to the predicate. The summary focuses on features of the device rather than numerical performance data in the provided text.
2. Sample Size Used for the Test Set and Data Provenance
This information is not provided in the excerpt. For an in vitro diagnostic device validation study, a "test set" would typically refer to patient samples used to evaluate accuracy, precision, and other analytical performance characteristics. The document mentions "specific data on the performance of the system" in Section V, which would likely include details on the test samples used, their number, and possibly their origin.
3. Number of Experts Used to Establish the Ground Truth for the Test Set and Qualifications of Those Experts
This information is not applicable and therefore not provided for this type of in vitro diagnostic device (reagent for quantitative determination). "Ground truth" for a chemical measurement in clinical chemistry is typically established by reference methods or highly accurate analytical instruments, not by expert interpretation.
4. Adjudication Method for the Test Set
This information is not applicable and therefore not provided for this type of in vitro diagnostic device. Adjudication methods like "2+1" are relevant for subjective interpretations (e.g., medical image assessment), not for quantitative chemical measurements.
5. If a Multi Reader Multi Case (MRMC) Comparative Effectiveness Study Was Done, If So, What Was the Effect Size of How Much Human Readers Improve with AI vs Without AI Assistance
This information is not applicable and therefore not provided. This device is a diagnostic reagent, not an AI-assisted diagnostic tool.
6. If a Standalone (i.e., algorithm-only without human-in-the-loop performance) Was Done
This information is not applicable and therefore not provided. This device is a chemical reagent, not an algorithm.
7. The Type of Ground Truth Used
For the performance assessment of this in vitro diagnostic reagent, the "ground truth" would implicitly be established through:
- Reference materials/known concentrations: For accuracy and linearity studies, the device's measurements would be compared against samples with known, precise magnesium concentrations.
- Comparison to a legally marketed predicate device: The core of a 510(k) submission is to demonstrate that the new device performs equivalently to an existing, cleared device. Therefore, the predicate device's results often serve as a de facto "ground truth" or benchmark for demonstrating substantial equivalence on patient samples.
- Internal validation against established analytical methods: The performance data in Section V would likely include comparisons to established analytical methods for magnesium quantification to ensure accuracy and precision.
8. The Sample Size for the Training Set
This information is not applicable and therefore not provided. This device is a chemical reagent, not a machine learning algorithm that requires a "training set."
9. How the Ground Truth for the Training Set Was Established
This information is not applicable and therefore not provided. As above, no training set is relevant for this device.
§ 862.1495 Magnesium test system.
(a)
Identification. A magnesium test system is a device intended to measure magnesium levels in serum and plasma. Magnesium measurements are used in the diagnosis and treatment of hypomagnesemia (abnormally low plasma levels of magnesium) and hypermagnesemia (abnormally high plasma levels of magnesium).(b)
Classification. Class I.